(a) Field of the Invention
The present invention is related to a rotary valve, and more particularly, to one that is provided with an air inlet and an air outlet passages and allows the connecting configuration of the passage be changed by a rotary valve block.
(b) Description of the Prior Art
Usually, pneumatic or hydraulic system is required in a mechanical operation mechanism or control system to transmit power or linkage signals. In the passage of such pneumatic or hydraulic system, valves are required. As there are too many types of valves available depending on the nature of machine, the present invention is related only to the valve adapted to an air filtration equipment such as an oxygen generator. For such an oxygen generator, an air compressor motor is used to drive an air pumping structure to fetch the air from the atmosphere. The air is then directed into an oxygen filtration unit to fit out oxygen, which is essentially used for medical purpose, or any other place or equipment that requires the consumption of oxygen. However, a solenoid is used in the passage of said oxygen filtration unit to control the timing of air inlet and release through the filtration unit while the timing to activate the solenoid is controlled by a separately provided circuit. Therefore, the adaptation of the circuit for the solenoid makes the oxygen generator move complicate and the solenoid is an expensive item to make production cost relatively higher. More precision circuit design depending on the electronic control in turn attracts higher failure frequency making the service life of the circuit shorter.
The primary purpose of the present invention is to provide a rotary valve with an air inlet and an air outlet passages for the same valve block and the connecting configuration of the common passage can be changed to control air inlet and exhaust. To achieve the purpose, the body of the valve includes a valve seat containing a rotary circular valve comprised two abutted semicircular blocks. Wherein, an accommodation space is provided in the valve seat. An axial plunger is provided each respectively in the upper and the lower sides of the semicircular valve blocks. Inside the two semicircular blocks, an air inlet and outlet passage is respectively formed extending from the periphery to the axial plunger, and a trough in a proper arc length is provided on the periphery in relation to the opening of the passage. A hole is provided on the periphery of the valve seat penetrating into the valve to connect the troughs and the passages. A linkage mechanism is provided to introduce the power to rotate the circular valve block so that during the rotation trip of the two semicircular blocks, a specific timing is provided for the troughs in relation to the hole of the valve seat to control the operation of air inlet and air outlet.